Recently, in various fields including the fields of electric and electronic apparatuses, automotive parts, and others, there are demands for mechanical strength associated with making those products thinner and lighter, and social needs for environment-friendliness associated with dehalogenation. In response to this, a transition from existing commodity bromine-based flame retardant resins, represented by polystyrene (PS) and ABS resin (acrylonitrile-butadiene-styrene resin), to phosphorous-based (phosphoric acid ester compound, etc.) flame retardant polycarbonate (PC) resins or the flame retardant PC/ABS alloys is under way.
However, since the phosphorous-based (phosphoric acid ester, etc.) flame retardant PC resins and the flame retardant PC/ABS alloys have a large amount (a few percent by weight to more than ten percent by weight) of a phosphorous-based flame retardant being added thereto, there are some problems that a gas generation may occur at the time of mold injection and that physical properties of the resin would significantly drop when it is recycled or placed under accelerated deterioration conditions (against high-temperature and high-humidity). These problems may all be considered due to that the phosphorous-based flame retardant hydrolyzes the PC component, especially under the high-temperature and high-humidity conditions.
On the other hand, a polycarbonate resin which is substantially free of the above-mentioned halogens such as bromine and phosphorus has also been developed. For example, Patent Documents 1 and 2 disclose a polycarbonate resin composition in which a silicone containing functional groups or this material with an organic alkali metal salt is added thereto as a flame retardant.
Patent Document 1: Japanese Patent Application Laid-open No. 2004-143410
Patent Document 2: Japanese Patent Application Laid-open No. 2005-54085